The field of this invention is compact electrical controls, and in particular a miniaturized form of a switch or a variable resistor.
There are several types of variable resistors. A rheostat is one which has a first terminal connected to one end of a resistance path and a second terminal connected to a contact that slides along the length of the resistance path to vary the resistance value. Another type is a potentiometer which has a separate terminal connected to each end of a resistance path, and a third terminal connected to a sliding contact that moves along the resistance path. The potentiometer acts as a voltage divider, to divide a voltage applied across the resistance path according to the position of the contact that moves along the resistance path. The present invention can be utilized in either of these forms or as a switching device where a rotating disc makes and breaks connections with the terminals.
The trend towards miniaturization of electrical apparatus has made it necessary to develop dependable electrical controls which are much smaller than previously required. A need has also developed for less expensive minature controls. Heretofore, it has been difficult to make an inexpensive, compact electrical control which is not only moisture proof, but also which is accurate and will retain selected settings.